"At this time there are no suspicious circumstances apparent to me in relation to this death."

Detectives are talking to witnesses, friends, colleagues and Mrs Saldanha's telephone contacts, DCI Harman said, in order to establish the circumstances that may have led to and contributed to her death.

Referring to the two Australian radio presenters who made the prank call, he added: "You will be aware of the wider circumstances in this case and I can expect in the very near future we will be in contact with colleagues in New South Wales to establish the best means of putting the evidence before you."

The coroner opened and adjourned the inquest, with a full hearing listed for March 26 next year.

None of Mrs Saldanha's family attended the hearing, but one of her colleagues was there, and the coroner said: "Can I express my sympathy to you and to the family."

Mrs Saldanha was a nurse at King Edward VII hospital, West London, where the Duchess of Cambridge was being treated for morning sickness.

Keith Vaz, the Labour MP who is helping the family, said a memorial service would be held in Bristol tomorrow, followed by one in Westminster Cathedral on Saturday.

He did not attend the hearing but said: "I have been asked to come here by the family. I have just spoken to the family on the telephone and I have repeated the brief statement given in court.

"The family is very grateful to the coroner's court for the way they have dealt with the matter and they are extremely grateful to the Metropolitan Police.

"They are grieving in their homes, they are comforting each other and the community is comforting them, that is why they have not come, it would have been a very long journey for a very short statement."

Last night, it emerged the broadcasters responsible for airing the call are to be officially investigated by the Australian Communications and Media Authority, which regulates radio broadcasting.

A spokesman said the station's licensee, Today FM Sydney Pty Ltd, will be investigated in line with the Commercial Radio Codes of Practice

Chris Chapman, Chairman of the ACMA, said: "The ACMA's formal regulatory relationship is always with the relevant licensee (and not the presenters of any broadcast in question).

"The ACMA will be examining whether the licensee has complied with its broadcasting obligations."

The family of the nurse are set to receive more than £300,000 from southern Cross Austereo, the parent company of Sydney station 2 Day FM, whose presenters were behind the prank call.

The hearing comes on the day that Southern Cross Austereo (SCA) is to resume advertising on 2 Day FM. All profits from the adverts until the end of the year will be donated to a memorial fund established in aid of Ms Saldanha's husband and teenage children.

A minimum contribution of £320,000 will be made, the company said.

SCA chief executive Rhys Holleran said on Tuesday that he hoped to help provide the Saldanha family with support "at this very difficult time."

Labour MP Keith Vaz has been campaigning on behalf of the nurse's husband Benedict Barboza, daughter Lisha, 14, and son Junal, 16, and has called on King Edward VII's Hospital, where she worked, to hold a full inquiry and offer further support to her family.

It has been reported that the family did not know about the hoax call until after Ms Saldanha's death.

The Labour MP has said: "They want the facts to be established so that they can effectively grieve.

"What is needed, clearly, is an inquiry by the hospital into how this tragic case happened."

In response to Mr Vaz's criticism, the hospital said its chief executive, John Lofthouse, spoke to the nurse's husband by phone on Friday and offered to meet him whenever he wanted.

The hospital has also established a memorial fund in Ms Saldanha's name to provide financial support for her family, and made the first donation to the fund.

Mr Vaz has written to Mr Holleran, claiming that his company has yet to make any direct contact with Ms Saldanha's family.

The MP, who is chairman of the House of Commons Home Affairs Committee, conceded there had been a public apology for the incident and its consequences through the media.

During the hoax call, the nurse transferred the DJs, believing they were the Queen and Prince of Wales, to a colleague who described in detail the condition of the Duchess of Cambridge during her hospital treatment for severe pregnancy sickness.

Ms Saldanha, 46, from Bristol, would have been devastated by her unwitting role in last Tuesday's scam, her brother has said. She was found dead three days later in a block of nurses' flats close to the hospital.

It is understood the family is making arrangements to return Ms Saldanha's body to her native India.

The two Australian DJs behind the hoax call – Mel Greig and Michael Christian – have given an emotional account of their reaction to Ms Saldanha's death.

Interviewed on Australian TV networks, the 2 Day FM presenters said their prank call to the hospital prompted "a tragic turn of events no one could have predicted or expected".

David Cameron paid tribute to Ms Saldanha and said MPs' sympathies and condolences would be with her family.